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Democracy in Action

I love being in the middle of a thunderstorm – being in the center of the light, noise and heavy rain is a really exhilarating experience. But new research from NASA’s Cassini probe makes me think that maybe Saturn would be an even better place to experience a massive storm.

Saturn’s huge size obviously explains why thunderstorms are so much bigger there than on Earth, but is that the only reason? Saturn, Jupiter and the other gassy planets are actually always bound to have more huge storms like this, because unlike our planet, their atmosphere is the planet, not just a thin layer on top of loads of rock.

Cassini’s discovered some other cool things about Saturn too – a 2000-mile wide storm near the South Pole that looked like a hurricane was discovered back in 2006, and of course Saturn’s many moons are proving to even more interesting than the giant planet itself.

That’s why it’s great news that NASA recently announced that funding for Cassini will continue until at least 2010 – hopefully even longer. Go Cassini!

As if it’s not already cool enough with its methane lakes, Grand Canyon-like geological features and status as the only moon in the Solar System with a thick atmosphere, Saturn’s moon Titan may now have yet another thing to show off about: NASA thinks that lying underneath its surface is a huge ocean of water and methane.

OK, it may be 63 miles below the surface, but the possibility of an ocean on Titan really is exciting, especially as it is thought to contain H2O – water. As we all know, water equals life and although Titan probably isn’t home to ET, the fact that another body in our Solar System has liquid water brings us increasingly closer to discovering life outside Earth.

But wait a minute… if the ocean is underground, and above the ground there is a dense, opaque atmosphere, how can we tell that there is an underground ocean? After all, as it’s 63 miles below ground you could hardly drill down into it.

Basically, it all began when a strange discovery started puzzling scientists: they were using radar on the Cassini probe to track the locations of various landmarks on Titan’s surface, but they found that the landmarks were moving between each flyby of Cassini. It could have been down to winds, but they would have had to be incredibly strong since some of the landmarks moved an amazing 20 miles.

The only plausible theory seems to be that the whole surface of Titan is floating on one massive ocean, and as currents in the ocean move the overlying land along, the landmarks move.

I’ve said many times before how amazing the Cassini mission to Saturn and its moons has been – take the recent flyby through the icy geysers of Saturn’s moon Enceladus for example. The great news is that NASA has decided to extend Cassini’s mission beyond its original scheduled finish this summer, meaning we’ll be discovering a whole load more weird and wonderful things about the ringed planet and its companions in the years to come. Go Cassini!

These images show Saturn’s moon Enceladus, as captured by the Cassini spacecraft. It recently flew through the plumes from Enceladus’s icy geysers, and took some photos either side of the flyby.

The surface of Enceladus may look like rock, but it is actually ice. Amazingly, there may even be a liquid water ocean underneath. Unforunately we’ll have to wait a while yet for the results of the geyser flyby to come back, but in the meantime…

Until a couple of years ago, Saturn’s moon Enceladus (that’s en-sell-uh-duhs) was thought to be pretty boring – it was just another cold lump of rock like our own Moon. But then two years ago, the Cassini probe discovered something that revolutionized our view of Enceladus: around its South Pole are geysers spewing ice, dust and gas into space. In fact, Enceladus is also thought to be one of the most likely places in our Solar System to find life.

But it’s not just huge geysers that make Enceladus interesting. Think how Yellowstone’s Old Faithful works – it’s all down to the heat of the Earth warming up the water so that it shoots upward. It’s not much different on Enceladus – in fact, Enceladus is a very geologically active body, and is among only two other Solar System bodies that have been seen erupting (the other two are Jupiter’s moon Io and Neptune’s satellite Triton).

Unlike on Earth where magma is the hot material, it is thought to be water-based on Enceladus. What causes the heat in a body so far away from the Sun? The main theory is that Saturn’s gravitational pull causes ‘tidal friction’, which generates heat in this otherwise icy moon.

Wait a minute… water, heat – they’re two key ingredients for life. It is indeed one of the places NASA is concentrating on in the search for ET. Enceladus is fast turning into one of the most exciting, revolutionary places in our Solar System – I can’t wait for the discoveries to come in the weeks and months ahead.

Everyone knows that Saturn has rings, but what about its moons? Surely they don’t have rings as well? Well actually, Rhea, a moon of Saturn that is usually overlooked, may be the first moon ever discovered to have rings, thanks to new research from the NASA/ESA Cassini-Huygens mission.

Rhea’s rings aren’t particularly impressive compared to Saturn’s – after all, it’s hard to imagine anything having a more impressive ring system that the huge gas giant Saturn. In fact, they haven’t even been photographed yet, but there is strong evidence to show that they exist.

How did the scientists work out that Rhea had rings without even seeing them? It’s all down to electrons, tiny charged particles that surround Saturn in its magnetic field. Because Rhea lies within the magnetic field of Saturn, it was expected to be seen ‘clearing up’ some of the electrons, because Rhea would absorb electrons from the magnetic field.

Rhea certainly did clear up the electrons – but it did it far better than expected, absorbing electrons about 7 times further away than it should have done. Why? The only feasible answer seems to be that Rhea has a ring system, and that the ring particles are absorbing the extra electrons.

Rhea is just one of a group of Saturn’s 52+ moons that are intriguing scientists: Rhea’s cousin Titan has methane lakes and rain; Iapetus is half-black and half-white; Enceladus has an atmosphere. The Cassini-Huygens mission is making it obvious that Saturn’s moons are just as interesting as the ringed planet itself.